Automotive finishing is a highly automated process. A running paint line processes a variety of colors and paint systems.
Between two applications, material lines must be flushed, paints changed and the associated process parameters loaded.
The plant control system can check whether valves have switched, which paint program is active and whether defined pressure and flow values are reached. However, this does not yet confirm that the expected material is actually leaving the atomizer with the desired spray behavior.
Errors can arise, for example, from:
- incomplete cleaning,
- residual material in the lines,
- incorrect material assignment,
- problems during color change,
- unsuitable mixing ratios or
- incorrect atomizer parameters.
If such an error is only detected on the car body, the effort involved is considerable.
Checking the Spray Before the Actual Application
An additional safeguard is a short, automated spray test immediately before painting.
For this purpose, the robot moves to a defined home or test position. There, the spray jet is briefly activated and optically analyzed.
Only when the measured spray matches the previously defined reference state is the atomizer released for the actual application.
This creates an additional quality check between material change and vehicle painting.
Testing with SprayQuantAI®
During this short spraying sequence, SprayQuantAI® can check, among other things:
- droplet size,
- droplet velocity,
- droplet count,
- relative changes in material flow and
- deviations from the approved spray state.
This makes it possible to determine whether the correct atomization has been achieved and whether the current state differs significantly from the stored reference.
Since the measurement works continuously, an assessment is possible even during a short test.
Material Testing with ParticleTensorAI®
If the material characteristics are to be tested in addition to the spray state, ParticleTensorAI® is used.
The AI-based analysis of the optical signatures compares the current material state with previously stored references. This also makes it possible to check whether the atomized material behaves optically like the expected paint system.
For an extended test station, for example, the LSS1 and LSS2 measurement probes can be combined, or a multichannel solution based on the LSS4 can be used.
Automatic Release Before Painting
The measurement results enable a simple automated sequence:
- The atomizer moves to the test position and the spray is briefly activated.
- SprayQuantAI® or ParticleTensorAI® analyzes the current state.
- The software performs a target/actual comparison with the stored reference state.
- If the spray is within the approved range, the plant control system receives an OK signal and painting begins.
- In the event of a significant deviation, the process is stopped or renewed cleaning or testing is triggered.
An Additional Quality Stage for Color Changes
The spray pretest does not replace existing plant monitoring. It complements it with a direct check of the result immediately before application.
Instead of only checking whether the plant has executed the intended sequence, it also checks what actually leaves the atomizer.
This way, errors in color change, cleaning, material logistics or atomizer settings are detected before paint reaches the vehicle.
SprayQuantAI® and ParticleTensorAI® thus enable automatic spray release immediately before the coating process.